Q 11-04-084JEE MainJEE Main 2024 (27 Jan, Shift 1)Easy
A body of mass $1000\ \text{kg}$ is moving horizontally with a velocity $6\ \text{m s}^{-1}$. If $200\ \text{kg}$ extra mass is added, the final velocity (in $\text{m s}^{-1}$) is:
Answer: (D) 5
No horizontal external force acts, so horizontal momentum is conserved:
$$1000\times6 = (1000+200)\,v \;\Rightarrow\; v = \frac{6000}{1200} = 5\ \text{m s}^{-1}$$
Solution by Sreeraj P, M.Sc Physics